In some cases, software can be updated by adding a file to, or deleting files from, an existing installation. When the files have the same name or identifier between software versions, the old file can be overwritten with the new file version.
In other cases, software can be updated by modifying the contents of an existing file. For example, lines of code in a file can be removed, modified, added, or otherwise changed in (such as being moved within) the file.
In some cases, software may have a primary version, such as a version in which the software was originally released, or a version representing a significant update to the software. Between versions, smaller updates, or code changes, may be made to a software version, such as to correct errors, add features, or improve performance.
Whether a particular software update or other code change can be applied to a particular software installation can depend on both the base version of the software and any incremental updates that have been applied. That is, later code changes may modify, use, or otherwise rely upon earlier code changes. If the particular software installation does not have the necessary base version or incremental updates for the particular software update to be applied, in some cases, the base version and earlier incremental updates can be first applied to the particular software installation.
However, fully updating the software installation may not be ideal. For example, it may take significant time for the updates to be applied to the software installation. During the update process, the software may not be available, which may inconvenience users. Updating the software may also require technical expertise, which can require paying for technical services or using in house technical personnel. Changes to software code may also cause changes in functionality or performance that may reduce its usefulness. For example, a fix to one feature of interest to a customer may modify another feature in a way that is not desired by the customer. Thus, room for improvement remains in the technical area of updating software.